I've been reading the postmortems in Game Developer for years. Subscriptions are free to anyone in the game industry who is willing to answer "Yes" to the obvious "Answer yes to this question and you'll get a free subscription" question on the application. Apparently you have to know a subscriber to get that form though.
The trouble with these postmortems is that they are pretty much always the same. They go something like this:
What went right:
* Lots of iteration
* Experienced team
* Early focus on tools
* Lots of control over scope
* Took advantage of feedback from actual players
* Partnership with company we like
What went wrong:
* Not enough iteration
* Absolutely horrible scheduling
* Out of control scope
* Poor tools
* Trouble hiring good people
* Partnership with company we don't like
Sometimes the specific headings are a little different, but usually the content comes around to one of these. The trouble is that there are so many disciplines at work on a game that the top 5 bullet points are never specific enough to actually benefit anyone. It's all well and good to say that you should have a well-scoped schedule with plenty of time for iteration and tools, but actually pulling that off is much more difficult. The postmortems never go into specifics on HOW because they are only 5 pages long.
A better way to get useful information is to attend one of the postmortem talks at the Game Developer's Conference. The best way is to hang out at a bar with one of the developers long enough that the drink loosens their tongues. Unfortunately none of those approaches scale, so I still find myself reading those Game Developer postmortems and wishing there were more details.